A photovoltaic device having a substrate, a layer of Cd.sub.2 SnO.sub.4 disposed on said substrate as a front contact, a thin film comprising two or more layers of semiconductor materials disposed on said layer of Cd.sub.2 SnO.sub.4, and an electrically conductive film disposed on said thin film of semiconductor...http://www.google.es/patents/US5922142?utm_source=gb-gplus-sharePatente US5922142 - Photovoltaic devices comprising cadmium stannate transparent conducting films and method for making
